Low potassium generally refers to hypokalemia, an abnormal state in which the concentration of potassium ions in human blood is reduced. Normal human serum potassium concentration is 3.5-5.5mmol/L, when the serum potassium is lower than 3.5mmol/L, it is hypokalemia, often caused by insufficient potassium intake, excessive potassium loss, metastatic hypokalemia, etc. 1, insufficient potassium intake: mostly seen in patients who cannot eat, paranoid, anorexic, because the daily required potassium is mostly taken in from the diet, long time can not be replenished with sufficient potassium through diet, it will Causes low potassium; 2. Excessive potassium loss: excessive potassium loss from the kidneys can be caused by kidney disease, endocrine disease, diuretics, etc. Excessive potassium loss from the digestive tract may be caused by massive vomiting, diarrhea, etc. Other excessive potassium loss is seen in large burns, long-term high temperature work, etc.; 3. Transferred hypokalemia: that is, transfer of potassium ions from extracellular to intracellular, mostly seen in alkalosis or recovery from acidosis, generally for every 0.1 increase in blood pH, blood potassium drops about 0.7 mmol/L. It is also seen in periodic paralysis, acute stress state, repeated input of cold storage washed red blood cells, etc. If patients experience weakness, limb weakness and abdominal distension, they need to be alert to the possibility of hypokalemia. It is recommended to visit the hospital for examination and timely correction.